The invention relates to a device for printing-pressure control in printing presses.
Devices are known for setting the printing pressure between an offset cylinder and printing cylinder so that a print of requisite quality will be obtained. One of the conventional devices has been disclosed in the German Pat. No. DE 1561071. In the foregoing device, the printing pressure is set by means of a first hydraulic cylinder acting via a toggle-lever mechanism upon the cylinders. A second hydraulic cylinder is provided is the known device as the adjustable cylinder. If the axial distance between the cylinders of the printing press changes beyond an adjustable dimension, pressure in the second hydraulic cylinder will rise and a pressure regulator arranged in the hydraulic supply line connected to the second hydraulic cylinder will interrupt the oil supply to the first hydraulic cylinder. This arrangement serves as the overload protection.
This device will only allow setting of the printing pressure but not regulating the printing pressure. The control of the printing pressure which has been set according to the operator's feeling can only be effected by controlling the results of printing and this will result in waste paper or in the fact that not all prints will be commensurate with the quality requirements.